Sift cream of tartar and soda with flour and oatmeal and sugar, cut in shortening, add milk a little at a time to make dough stiff enough to roll. Divide dough into two parts and roll out separately to about 1/4 inch thickness, sprinkle with a little oatmeal & sugar before cutting into cookies. Bake in moderately hot oven bout 10 to 15 mins.